Explain how to run WebAssembly module from browser console

[jspaaks]

moved this snippet from https://github.com/NLESC-JCER/run-cpp-on-web/blame/2abe8c363736c4aae4f8176def9668bd531230ef/js-plot/README.md#L164-L181 to an issue:

<!--
TODO do we want to explain how we can run snippet below?

To run test the WebAssembly module in a web browser we can use it's build-in console

1. startup a web server to host newtonraphson.js and newtonraphson.wasm with `python3 -m http.server 8000`
2. goto webserver adress [http://localhost:8000](http://localhost:8080) in browser
3. open the console in the web browsers DevTools (press F12 to open)

Import the WebAssembly JavaScript binding file with

```javascript
const response = await fetch('http://localhost:8000/newtonraphson.js');
const text = await response.text();
eval(text);
const {NewtonRaphson} = await createModule();

-->